[build] Remove remaining dependencies on libatomic, for Android, BSD, and Haiku

Follow suit from linux, #29581, tested on Android.

Author: finagolfin

cmake/modules/AddSwift.cmake

@@ -417,10 +417,10 @@ function(_add_variant_link_flags)
     list(APPEND library_search_directories
          ${CMAKE_BINARY_DIR}/winsdk_lib_${LFLAGS_ARCH}_symlinks)
   elseif("${LFLAGS_SDK}" STREQUAL "HAIKU")
-    list(APPEND link_libraries "bsd" "atomic")
+    list(APPEND link_libraries "bsd")
     list(APPEND result "-Wl,-Bsymbolic")
   elseif("${LFLAGS_SDK}" STREQUAL "ANDROID")
-    list(APPEND link_libraries "dl" "log" "atomic")
+    list(APPEND link_libraries "dl" "log")
     # We need to add the math library, which is linked implicitly by libc++
     list(APPEND result "-lm")
 

stdlib/public/core/CMakeLists.txt

@@ -256,19 +256,13 @@ else()
   endif()
 endif()
 
-if(SWIFT_PRIMARY_VARIANT_SDK STREQUAL ANDROID)
-  # workaround for libatomic needing to be after object files for swiftCore.so
-  list(APPEND swift_core_private_link_libraries atomic)
-elseif(SWIFT_PRIMARY_VARIANT_SDK STREQUAL CYGWIN)
+if(SWIFT_PRIMARY_VARIANT_SDK STREQUAL CYGWIN)
   # TODO(compnerd) cache this variable to permit re-configuration
   execute_process(COMMAND "cygpath" "-u" "$ENV{SYSTEMROOT}" OUTPUT_VARIABLE ENV_SYSTEMROOT)
   list(APPEND swift_core_private_link_libraries "${ENV_SYSTEMROOT}/system32/psapi.dll")
 elseif(SWIFT_PRIMARY_VARIANT_SDK STREQUAL FREEBSD)
   find_library(EXECINFO_LIBRARY execinfo)
   list(APPEND swift_core_private_link_libraries ${EXECINFO_LIBRARY})
-  # workaround for libatomic needing to be after object files for swiftCore.so
-  list(APPEND swift_core_private_link_libraries
-    ${SWIFTLIB_DIR}/clang/lib/freebsd/libclang_rt.builtins-${SWIFT_PRIMARY_VARIANT_ARCH}.a)
 elseif(SWIFT_PRIMARY_VARIANT_SDK STREQUAL LINUX)
   if(SWIFT_BUILD_STATIC_STDLIB)
     list(APPEND swift_core_private_link_libraries swiftImageInspectionShared)